Method for manufacturing counterweights

ABSTRACT

A work piece and a method for making the work piece from a plurality of grains of substantially cohesive scrap metal grains or granules is disclosed. The method includes providing scrap metal as a raw material, gathering a predetermined amount of the raw material to form a charge, and compressing the charge under a predetermined amount of heat and pressure to provide a substantially cohesive form. To aid with the cohesion, the charge may be enclosed within a polymeric container or bag which acts as a lubricant during the compression stage and as a binder to aid in keeping the scrap metal together in a cohesive form.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to earlier filedU.S. provisional patent application Ser. No. 60/621,492 filed Oct. 25,2004, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to the recycling of raw materials, andparticularly to a method for using those raw materials in a new andunique process for making counterweights.

BRIEF DESCRIPTION OF THE RELATED ART

Many devices including cranes, forklifts and other large machinery usedfor lifting heavy objects, and microphone stand among other devices, usecounterweights to keep the objects from tipping over when used.Counterweights are also used for other purposes such as providing asource of power. For example, grandfather clocks have a series ofweights used to power the clock mechanism. Traditionally these weightshave been made from cast iron or standard commercial grades of steel,cut, stamped, or molded into specific shapes. Moreover, a substantialnumber of counterweights used today do not serve any structural purpose.In most instances, they are only a ballast to provide weight in theproper location so that the object functions as intended.

File cabinets used in offices also typically have a large mass in theback of the cabinet, behind the lower drawer boxes, to keep the cabinetfrom tipping over when a heavy drawer is opened. The size of the mass isdetermined by the anticipated weight of the contents in the filingcabinet drawers, how far each drawer is allowed to open, and whether ornot other drawers are allowed to open at the same time.

In the past, different types of counterweights have been used to helpstabilize file cabinets. The different types of materials are selectedbased upon the volume of the space available as well as the density ofthe material. The most often selected material has been steel platebecause it does not require a substantial volume, can be easily stampedto the desired shape or area, and because of its weight. However,because of the ever increasing cost of steel, alternative sources of rawmaterial for making counterweights must be explored.

Most counterweights used in file cabinets are not structural parts, andonly function as mass. Therefore, material properties such as strengthare not an issue. The disadvantage of current counter weight systems isthat manufacturers are using original raw materials to manufacture suchweights. Iron and steel are being worked in forges to produce moldedobjects or plate steel that is cut or otherwise stamped to the desiredshape, let alone worked again and again to produce a desired shape. Itis certainly a purpose of this invention to provide a novel and uniquemethod for manufacturing counterweights at a lower unit cost thancurrently available, while at the same time reducing the demand on rawmaterials.

SUMMARY OF THE INVENTION

According to one form of the invention, a method is described forforming an object from scrap metal, comprising the steps of obtainingscrap metal for a source; organizing the scrap metal into predeterminedclasses based upon at least one criterion; forming a charge from atleast one class of scrap metal; and compressing the charge into apredetermined shape. The method may be modified by of enclosing thecharge within a polymeric container that may act both as a lubricantduring the compression stage, and as a binder as a result of the polymerflowing in between at least some of the grains of scrap metal andsubstantially surrounding the finished form. Additional forms of theinvention may include performing processes prior to the forming stageincluding the removal of contaminants and sorting of the scrap metalbased upon one of size, type, and grade.

According to another form of the invention, a method is provided formaking a non-structural work piece from scrap metal as a raw material,including sorting the raw material into at least one class based upon atleast one criterion; enclosing a predetermined amount of the rawmaterial in a container to form a charge; and pressing the charge into apredetermined shape. To aid in the forming of the shape, the inventionalso contemplates using the container to act as a lubricant and as abinding agent when the pressing step has been substantially completed.

In yet another form of the invention, it is contemplated that a suitableforming method is to compress the charge into one of a briquette orforming the charge by way of cold forging.

In another form of the invention a method for making metallic workpieces is disclosed, comprising providing scrap metal as a raw material;enclosing a predetermined amount of the raw material in a polymeric bagto form a charge; and compressing the charge under a predeterminedamount of pressure to form the work piece.

The work piece resulting from the method is comprised of a plurality ofgrains of scrap metal compressed into a substantially cohesive form; anda polymeric material covering a substantial portion of the substantiallycohesive form and at least a portion of said plurality of grains ofscrap metal.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The sole drawing FIGURE in the application constitutes a flow diagramillustrating the basic steps of the invention

DETAILED DESCRIPTION OF THE DIFFERENT EMBODIMENTS

For purposes of the following description, the terms “upper,” “lower,”“left,” “rear,” “front,” “vertical,” “horizontal” and derivatives ofsuch terms shall relate to the invention as oriented on a particularpage. It is to be understood that the invention may assume variousalternative orientations and configuration, except where expresslyspecified, devices and processes illustrated in the attached drawingsand described in the following specification are simply exemplaryembodiments of the invention. Specific dimensions and other physicalcharacteristics relating to the embodiments disclosed herein are not tobe considered as limiting unless expressly stated otherwise.

The material for producing metallic work pieces such as counterweightsand like objects is metal scrap often disposed of by other manufacturersas a waste by-product. The invention need not be specific to anyparticular form of scrap, although it is anticipated that the grade ofscrap may become an important issue in certain manufacturing methods.For the purposes of this invention, the grade and type of metal scrapwill not be considered a limiting factor. However, the followingdescription will be given with respect to metal waste or scrap producedin a typical milling or turning operation in a machine shop.

In one embodiment of the invention, a work piece such as a counterweightmay be manufactured by obtaining scrap metal from one of a number ofsources. The source may be internal to the operation of the business orthe scrap may be purchased from any one or more vendors who recycle suchmaterials. The gathering of the scrap metal is represented as box 12 ofthe flow chart 10 shown in FIG. 1. Regardless of how the scrap metal isgathered or obtained, it may be preferred to sort the scrap based uponone or more predetermined characteristics. This step is represented bystep 14 in FIG. 1. One such anticipated characteristic may be based uponcomposition—that is ferrous versus non-ferrous metals. Another basis forclassification may include size, purity, shape, density, etc. that canbe determined using any one of a number of sorting methods andtechniques. In addition, it may be desired to clean the scrap metal toremove any contaminants including, but not limited to, oils or othervolatiles that could later seep from the completed work piece or presenta hazard to workers and the environment during the manufacturingprocess. The sorting and cleaning processes have been combined for thepurposes of representing the steps in FIG. 1.

Once the scrap metal has been processed as minimally or thoroughly asdesired, a predetermined amount of the scrap metal is metered to formwhat will be referred to herein as a “charge.” See Step 16 in FIG. 1.The term “charge” as used herein is to refer to a predetermined volumeor amount of the scrap metal to be used in any subsequent process. Thecharge may be formed based upon the weight of the material.Alternatively a predetermined volume or cavity may be filled such asbucket of a loader or the like.

Once the charge of scrap metal is established, the forming process takesplace. The particular type of forming method may vary depending in largepart upon what, if any, subsequent processes will occur. For example, asrepresented by Step 18 in FIG. 1, it is contemplated that a user maysimply perform a single step forging method where the charge iscompacted and shaped at the same time. This type of process may be usedto produce a shape having a lesser density than by other methods, butcan be performed quickly with some degree of certainty that the shapewill be retained for at least a short period of time. Alternatively amore complex multistage compression technique may be used to compact thescrap metal into a more dense and cohesive form. It is envisioned that aforming technique may be used to introduce sufficient pressure topossibly cause some of the grains or granules of the scrap to fuse ormerge together. At the very least, it is envisioned that the techniqueused to compress the scrap metal will cause the different grain or pieceof metal scrap to adhere to one another in a cohesive fashion.

In an alternative form of the invention, metal shavings are routinelycollected by salvage vendors who either pay for the material or charge afee for removal depending on the grade of the material collected. Thevendor may then employ the invention or alternatively sell the scrapmetal shavings to another who would employ the process. In either event,one type or category of machinery that may be used in the invention isgenerally referred to as a “briquetting” machine. The recycler woulddispense a predetermined volume of steel shavings into the “briquetting”machine which is already configured to accommodate the amount of theshavings used. See Step 20 of FIG. 1. The briquetting machine is acommercially available device that compacts scrap material such as thesteel shavings or millings into a brick or cylinder. Although the commonform of the output from the briquetting machine may be a cylinder ofpredetermined length and diameter, it is also contemplated that thesetypes of machines may be easily altered or modified to produce output ofdifferent shapes. Machine shops often purchase briquetting machines tocompact their scrap into a more valuable form for sale to salvagers.

According to one specific form of the invention, the output frombriquetting machines can be used as a low cost raw material for theproduction of parts. See Step 20 of the flow diagram 10. If therequirements for the part are simple, the briquette may require nofurther processing and used as is. If the part form is more complex, thebriquette form may be placed into a die equipped with a cavity matchingthe desired shape of the final part and cold forged. The forging processincreases the density to the part and allows custom features to beadded.

The material for producing one form of a counterweight made according tothe invention is shredded steel scrap such as produced in a typicalmilling or turning operation in a machine shop. The shavings can beroutinely collected by salvage vendors who either pay for the materialor charge a fee for removal depending on the grade of the materialcollected. This is the raw material feedstock according to oneembodiment of the invention.

After collecting the scrap metal, it is envisioned that the materialwould be cleaned to remove any undesirable volatiles or environmentallyundesirable chemicals. To aid in either of the manufacturing or cleaningprocess, it is also contemplated that the scrap metal may be shredded toproduce a more uniform mix of chip sizes. Not only does the shreddingincrease the surface area of any cleaning, it also may be used to reducethe size variation of the material and make handling of the raw materialeasier.

After shredding the material and cleaning process, the raw materialscrap may be fed on to the compaction process. The compaction processwould most preferably compress the chips of scrap metal together into aninterlocking mass. In certain instances, the pressure may be applied byrolling the material between platens or rollers designed to compact thechips into a dense sheet. This process could be similar to cold-rollingsteel but with the aim of re-compacting the material and increasing thedensity. After rolling, the part may be die cut or sheared into smaller,more uniform and usable lengths and processed.

According to another form of the invention, the scrap metal is deliveredto the manufacturer, either from a vendor or from an in-house source.Regardless of the source of the scrap metal, the grain size of the scrapmay be made more uniform by passing the scrap through a grinding orshredding process. In addition the form of the grains or granules may bemodified. For example, it may be desired to work with grains or granulesthat are more plate like in shape. This plate-like appearance may beobtained by passing the scrap through a ball mill or similar percussiondevice.

With the scrap in a more uniform grain size, the material lends itselfto more conventional handling using conventional conveyor belts ormaterial handling processes. Using these types of translative methods,the scrap metal may be passed through a number of processes to removeany contaminants, undesirable coatings, or it may be separated basedupon density. This way, more refining of the scrap metal may beachieved.

Once the metal is passed through the refining process and sorted basedupon one or more of those characteristics, the scrap metal may bedispensed in predetermined amounts into polymeric bags or containers.The containers not only would serve to constrain the smaller grains ofscrap metal to an enclosed container, but the size of the container mayalso serve an additional function. As briefly mentioned, above the scrapmetal is measured into charges suitable to provide the proper materialfor a given process. In this embodiment, not only do the polymericcontainers contain the proper amount of a charge, but the containeritself may act as a lubricant during the compression or compactionprocess, requiring relatively little heat to cause the container tochange from a solid to a molten state. As the compaction processcontinues, the polymeric material housing the scrap is melted in amanner to form a protective coating over the exposed surfaces of thenewly formed object or work piece. In certain instances, the polymericmaterial may actually form a protective envelope over the work piece toreduce the exposure to oxidizing processes, contact with sharp pointsand edges, and overall a safer work piece. In either event, the changein state of the container from a solid to a molten or plastic state willact to bind some of the grains/granules together and provide a morecohesive form. Following the forming process, the finished form is readyto be used in the desired application as ballast or counterweight orother function.

The above description is considered that of the preferred embodimentsonly. Modifications of the invention will occur to those skilled in theart and to those who make or use the invention. Therefore, it isunderstood that the embodiments shown in the drawings and describedabove are merely for illustrative purposes and not intended to limit thescope of the invention.

1. A method for forming an object from scrap metal, comprising the stepsof: Obtaining scrap metal; organizing the scrap metal into predeterminedclasses based upon at least one characteristic of the scrap metal;forming a charge from at least one of said predetermined classes ofscrap metal; and compressing said charge into a predetermined shape. 2.The method as defined in claim 1, further comprising the step ofenclosing said charge within a polymeric container.
 3. The method asdefined in claim 1, further comprising the step of removing contaminantsfrom the scrap metal prior to the step of forming the charge.
 4. Themethod as defined in claim 1, further comprising lubricating the chargeduring the step of compressing.
 5. The method as defined in claim 1,wherein the step of obtaining scrap metal includes at least one ofacquiring the scrap metal from a third party and gathering the scrapmetal as a result of a bi-product internally.
 6. The method as definedin claim 1, wherein organizing the scrap based upon at least onecharacteristic comprises sorting the scrap metal based upon one of size,type, and grade.
 7. The method as defined in claim 1, wherein the stepof forming a charge includes defining a predetermined amount of thescrap metal using a predetermined metric.
 8. The method as defined inclaim 1, wherein the step of compressing the charge comprises subjectingthe charge to a predetermined amount of pressure and heat to cause thescrap metal to remain in a cohesive form.
 9. The method as defined inclaim 2, wherein the step of compressing causes the container to act asa binder.
 10. The method as defined in claim 2, wherein the step ofcompressing includes flowing at least a portion of the container aroundat least a portion of the scrap metal.
 11. The method as defined inclaim 2, wherein the step of compressing comprises melting at least aportion of the container into a least a portion of the scrap metal. 12.The method as defined in claim 3, wherein the step of removingcontaminants includes at least one of cleaning the scrap metal andsorting the scrap metal based upon meal type.
 13. The method as definedin claim 4, wherein the step of lubricating comprises the step ofplacing the scrap metal within a polymer.
 14. A method for making anon-structural work piece, comprising the steps of: providing scrapmetal as a raw material; sorting the raw material into at least oneclass based upon at least one criterion; enclosing a predeterminedamount of the raw material in a container to form a charge; and pressingthe charge into a predetermined shape.
 15. The method as defined inclaim 14, further comprising lubricating said charge during the step ofpressing.
 16. The method as defined in claim 14, further comprisingproviding a polymer to at least partially surround the raw materialduring the step of compressing.
 17. The method as defined in claim 14,wherein the step of compressing including producing a briquette.
 18. Themethod as defined in claim 14, wherein the step of compressing includesthe step of cold forging.
 19. A method for making metallic work pieces,comprising the steps of: providing scrap metal as a raw material;enclosing a predetermined amount of the raw material in a polymeric bagto form a charge; and compressing each charge under a predeterminedamount of pressure into a predetermined work piece.
 20. A work piece,comprising: a plurality of grains of scrap metal compressed into asubstantially cohesive form; and a polymeric material covering asubstantial portion of said cohesive form and encasing at least aportion of said plurality of grains of scrap metal.